Metal-screw machine



-4 Smate-sheet` 1,

(No Modelg,

J. HRTNBSS; A METAL SCREWMAVHINE..

No.v 502,517y Patzented` Aug. 1', 1893.'l

(No Model.) 4 Sheets-Sheet 3.

J. HARTNESS. 'METAL SCREW MACHINE.

No. 502,517. l PatentedAug. l, 1893.

UNITED STATES PATENT OFFICE.

.I AMES HARTNESS, OF SPRINGFILD, VERMONT.

METAL-SCREW MACHINE.

SPECIFICATION forming part of vLetters Patent No. 502,517, dated August 1, 1893.

Application tiled May 6, 1892. Serial No. 432,025 (No model.)

To @ZZ whom it may concern:

Be it known that I, JAMES HARTNEss, of Springfield, in the county of Windsor and State of Vermont, have invented certain new and useful Improvements in Metal-Screw Machines, of which the following is a specication.

This invention relates to that class of machines for making screws in which a Workholding and rotating chuck is employed, and a turret-slide provided with a turret adapted to be rotated on the slide and provided with a series of tools adapted to perform different parts of the operation o f forming screws, bolts, dsc., from a rod of metal, the chuck and turret-slide being mounted upon a suitable bed upon which the slide is movable toward and from the chuck, substantially as shown in Letters Patent of the United States No. 457,967, granted to me August 18, 1891,

The invention has for its obj ect, first, to enable the number of operative tools employed in a machine of this class to be increased Without crowding or over-loading the turret; and, secondly, to enable the stock to be fed forward through the chuck when the latter is opened, by gravitation, and the return of the turretslide to its starting position or the end of its backward movement to be facilitated by gravitation.

To these ends my invention consists in the construction and combination of parts as hereinafter described and claimed.

Of the accompanying drawings, forming part of this specification: Figure 1 represents a perspective view of a screw machine provided with my improvements. Fig. 2 represents a top view of a portion of the machine. Fig. 3 represents a side elevation of the opposite side of the machine from that shown in Fig. 1. Fig. 4 represents a section on line 4-4, Fig. 2, looking toward the left. Fig. 5 represents a perspective view of a portion of the machine. Fig. 6 represents an end elevation of the machine. Fig. 7 represents a section on line 7-7, Fig. 2, looking toward the left.

The same letters of reference indicate the same parts in all the figures.

In the drawings: a represents the bed of the lathe; b represents the turret-slide,which is movable upon said bed; and c represents the chuck, which holds and rotates the bar or rod d, which is converted by the action of the machine into the desired articles. For convenience, I will hereinafter call said bar or rod the stock.

The general construction, arrangement and operation of the machine are or may be the same as shown in the above-mentioned Letters Patent No. 457,967, and, as my present improvements relate only to the stock-stop, the independent die-carriage and the inclination of the bed, all as hereinafter described, I do not describe the machine as a Whole, but refer to said patent as showing a suitable machine to which my hereinafter described improvements are applicable.

e represents the stock-stop, which constitutes one of my improvements. Said stop is here shown as an arm pivoted at c to an ear or bracket b affixed to the turret-slide b, said arm being adapted to swing freely in a plane substantially at right angles to the direction of movement of the turret-slide, and provided at its swinging end with an adjustable screw e2, which, when the stop is in the position shown in Figs. 3 and 4, is in position to arrest the forward end of the stock when the latter is moved forward in the chuck. The arrangementof the stock-stop c is such that, when the turret-slide b is at the limit of its backward movement, and is arrested by the stop f employed to determine the extent of the backward movement of the turret, the stockstop will be in position to arrest the forward end o`f the stock d at the proper point, so that, after the stock has been grasped by the chuck and the stock-stop has been swung laterally out of line with the stock and with the turret, the turret may be advanced upon the stock andcaused to present one of its tools thereto. Thus the location of the stop facts, through the turret to determine the point at which the stop c will arrest forward movement of the stock.

I do not limit myself to the described means of supporting and moving the stock-stop, as it is entirely obvious that the stop may be moved to and from its operative position by a rectilinear instead of a swinging movement.

g represents the independent tool-carrier, which is arranged to carry a tool such as a screw-cutting die g', or, if preferred, a plu- IOO rality of tools, such as a screw-cutting die and a turning tool g2, and to present said tool or tools to the stock atapoint between the chuck and the turret. I have here shown the toolcarrier g in the form of an arm, rigidly affixed at one end to arod g3, whichis adapted both to slide and to turn in guides or bearings g4 g4, affixed to the bed a, said rod being parallel with the direction of movement of the turret-slide. The rod g3 is here shown as provided with an arm g5, rigidly affixed to the rod, and carrying in its swinging end a leadnut g, formed to engage a lead-screw Q7, which is journaled in suitable fixed bearings, and is rotated by the power of the machine, said lead-nut being a stud, affixed to a socket in the arm g5 by a set-screw or other suitable means, and having oneV of its ends provided with sections of a screw-thread corresponding to the thread on the lead-screw, so that, when the lead-nut gG is brought into engagement with the leadscrew, the rotation of the latter will immediately impart, through the lead nut and the arm g5, a longitudinal movement to the rod q3 and tool-carrier g. This arrangement of lead-screw and die-carrier is analogous to the ordinary chasing-bar mechanism, but differs from the latter in that the tool-carrier ghas a dieinstead of a single chasing-point such as is operated by the chasing-bar. There is, however, this difference, namely, in the chasing-bar lathe, the chasingtool is generally run over the work a number of times to cut the thread, while in the present case the thread-cutting die is adapted to cut the full thread at one cut. Another diference is that the tool-carrier is or may be provided with more than one tool.

When the tool-carrier is provided with a screw-cutting die and with a turning tool, as here shown, each tool may be brought into operative position with relation to the stock by a suitable swinging movement of the carrier g, the turning tool being used either for shaping the end of the work beyond the screwthreaded portion, or for turning the whole length of a piece, the same as in the turret turner.

Motion may be imparted to the tool-carrier when the turning tool is in use, by means of the turret, the latter being forced against the tool-carrier g to feed the tool into the work, such part of the turret being used as carries no interfering tool. After the turning tool has performed its operation, the carrier g may be swung inward until the screw-cutting die is brought into position, the arrangement being such that the movement of the carrier required to bring the screw-cutting die into position brings the lead-nut gsinto engagement with the lead-sere7 Q7, so that the action of the screw-cutting die is governed by the leadscrew.

I do not limit myself to the employment of the lead-screw in connection with the independent tool-carrier, arranged to present a tool to the stock at a point between the turret and the chuck, it being obvious thatsaid tool-carrier may be operated by other means than by the lead-screw, as above described; nor do I limit myself to the employment of the particular tools here shown in the independent tool-carrier g, but may provide said carrier with any other suitable tool or tools, the main object of saidl carrier, as well as of the stock-stop e, being to provide the machine with all the tools and appliances that may be desirable, without crowding or over-loading the turret.

Heretofore, the stock-stop, the screw-cub ting die and the turning tool have been supported entirely by the turret. I have found by experience that the maximum number of tools that the turret can carry is six (6), and that it is not practicable to increase this number. It is evident, therefore, that, if the turret is obliged to carry the screw-cutting die and the stock-stop, the number of additional tools which it carries must be curtailed; and that, by removing the stock-stop and the screw-cutting die from the turret, the range of usefulness of the latter is correspondingly increased.

Another feature of my invention is the inclination of the bed ct, for the purpose of causing the automatic feeding forward of the stock when the chuck is opened,and of facilitating the backward movement of the turret at the conclusion of its work. To this end, I give the bed an inclination, preferably, of about thirteen degrees (13), that end of the bed which supports the chuck being higher than the opposite end of the bed by a sufcient amount to give the bed, the axis of the chuck and the turret-slide, the desired inclination. This inclination enables the stock to move forward by gravitation when the chuck is opened, thus enabling the use of mechanism for feeding the stock into the spindle and chuck to be dispensed with. The inclination also enables the turret-slide to run back to its starting point more easily than if the bed were horizontal, so that there is but little effort required to return the turret to its starting position. It is well-known that, in machines of this class, the turret is carried toward the chuck by the feeding mechanism operated by power, and is returned to its starting point by the power of a hand-wheel. The inclination of the bed materially reduces the labor of the operator in returning the turret. The inclination of the bed may be at any desired degree. Vhen the inclination is gentle, and is about thirteen degrees (13), as here shown, the outer portion of the stock may be supported by an idle-roll r, on a suitable standard r', said roll enabling the stock to feed by gravitation when the chuck is opened. When the inclination is greater than that here shown, the roll in the stock-support r may not be required, because the friction would not overcome the tendency of the bar to slide down a steep inclination. If desired, more than one stock-supporting idle-roll may IOO be employed, and said rolls may be carried in a head, like that shown in Letters Patent No. 425,377; but, in such case, no mechanism would be employed to positively rotate the 5 rolls.

I do not limit myself to the employment of the inclined bed in'all cases, as the other improvements hereinbefore described may be employed in connection with a horizontal bed. ro I claim- 1. The improved lathe or screw machine, comprising in its construction a bed, a chuck, a turret-slide mounted to move thereon toward and from the chuck, and provided with I5 a tool-holding turretarranged to be presented to the stock held and rotated by the chuck, a stop to arrest backward movement of the turret, and a movable stock-stop or gage connected with the turret-slide and movable independently of the slide into and out of its operative position, said stop being arranged to be in its operative position when the turret-slide is at the end of its backward movement, as set forth.

' 25 2. In a lathe or screw machine, the combination with the bed, the chuck, the turretslide and the turret, of a stop to arrest backward movements of the turret, a stock-stop pivotally connected with the slide at a point 3o in advance of the turret, and adapted to swing or oscillate substantially at right angles with the direction of movement of the slide, into and out of its operative position, said stop being so located on the slide that it is in its op- 35 erative position when the slide is at the end of its backward movement, as set forth.

3. A turret lathe comprising in its construction a bed, a chuck, a turret-slide, a turret mounted on said slide, an independent 4o sliding bar on the bed, and an independent tool-carrier pivotally supported by said independent sliding bar, as set forth.

4. A lathe or screw machine comprising in its construction a bed, a chuck, a turret slide, a turret on said slide, an independent die carrier arranged to present a die to the stop at a point between the turret and the chuck, said die carrier having a plurality of tools, and means for moving said carrier independently, as set forth.

Y 5. A lathe or screw machine, comprisingin its construction a bed, a chuck, a turret-slide, a turret on said slide, and an independent tool-holder mounted on a carriage movable lengthwise ofthe bed, and mounted to swing 55 in a plane substantially at rightangles with the axis of the chuck, and provided with a plurality of tools adapted to be brought successively into operative position by the swinging movement of the carrier, the latter being arranged to present the said tools to the stock at a point between the chuck and turret, as set forth.

. 6. In a lathe or screw machine, the combination of the bed, the chuck, a single rod 65 movable lengthwise in guides on the bed and adapted to turn in said guides, the die-carrier rigidly aflixed to said rod, the lead-screw rotated by the power of the machine, and an arm also rigidly affixed to said rod and pro- 7o vided with a lead-nut adapted to engage said lead-screw, as set forth.

In testimony whereof I have signed my name to this specication, in the presence of l two subscribing witnesses,rthis 26th day of 75 April, A. D. 1892.

JAMES HARTNESS. Witnesses:

W. D. WooLsoN, G. Oris GRIDLEY. 

